From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Test results for a 28 slot armature for a 40/50 Dynamo, detailing adjustments and performance at different 'B angles'.
| Identifier | ExFiles\Box 68\4\ scan0019 | |
| Date | 8th August 1927 | |
| X8672 E.F.C. 8.8.27. Copy figures onto Gelig copy X.8672. 28 SLOT ARMATURE FOR 40/50 DYNAMO. The first 28 slot armature when run in standard carcase gave a B angle of 7° and low output. The second and third gave ditto. The B angle of the first was altered to 12° by altering connections one segment and output was then too high. The third armature had its B angle altered to 9.5° which is considered to be O.K. for correct output in standard carcase. For use of this armature in N.B. carcase, further tests of the three armatures will be made to determine suitable B angle. EFC. Result of further tests.— B angle. 7° 9.5° 12° M.P. curve { Max. amps. 12.9 13.3 12.3 } at 80°c { C. angle 121.5° 122.5° 125° } Ref. curve { C. angle 122.5° 125° 125.5° } " " { Max amps. 11.9 12.2 11.8 } | ||